Introduction to the Scaling of Aquatic Animal Locomotion

Abstract : This introductory lecture attempts to discuss the scaling problems related to the locomotion of aquatic animals in two major categories characterized by low and high Reynolds numbers of swimming motion. In the low-Reynolds-number flow regime it first gives a brief survey of flagellar and ciliary locomotion in order to ascertain the different key parameters that play a role. The hydromechanical and physiological performance of a group of micro-organisms, of different sizes but otherwise similar in their organization from the scaling point of view, is examined. In the high-Reynolds-number category, discussions of the scaling problems include the carangiform and lunate-tail locomotion of different groups of fishes and cetaceans, with consideration of hydromechanical efficiency and physiological function. The discussion is based on the data of both comparative zoology and dynamical similarity. (Author)